Water flow question for 5.7L

[justlakinit]

I fear my motor is not getting the proper water flow and I can't figure out why.
I just put in my 2nd replacement motor in three years.
My first motor burned a hole between cylinders 3 & 5 where the head meets the block.
It was a 1996 motor and I just assumed it wore out.
I replaced that motor with a reman. long block and it ran good for almost two summers before cracking the head and block between cylinders 2 & 4.
Never showed any signs of over heating on the temp gauge.
I had a marine survey company look at the motor and he said that I appeared that I had some blockage in my cooling system. This caused turbulence in my water flow which created air pockets between middle cylinders.
Because I had water flowing thru, it never showed hot on the temp gauge.
So now I have replaced the motor again...started it today and the water flow still seems lower than it should be.
I get good flow out one side of the exhaust but not the other.
I thought maybe I had a clogged riser, but disconnected the water supply going in got the manifolds on each side and started it, and still only got good flow on one side.
I then reconnected the hoses and clamped the hose that was getting good flow and I then got good flow out the other side, which tells me that it is not clogged on either side.
I took all the hoses off and flushed before installing the new motor.
Installed new water pump, and the impeller was installed new at the end of last season.
Any suggestions?????

 

[achris]

Re: Water flow question for 5.7L

Do a water pump output check, then put a section of clear hose in the incoming water line to ensure you getting a clear stream of water... Both these tests need to be done on the water, they can't be done on a hose....

Have an engine or drive serial number so we can check what the output should be?

Chris..........

 

[justlakinit]

Re: Water flow question for 5.7L

Eng. No. OF601305
Drive No. OF693057
Any help would be much appreciated.

 

[justlakinit]

Re: Water flow question for 5.7L

Any advice?

 

[achris]

Re: Water flow question for 5.7L

Your water pump output should be no less than 3.4 litres in 15 seconds at EXACTLY 1000rpm. The test MUST be done in the water (not on a hose) and done 4 times and the results averaged. You need to reconnect the water hose to the engine between tests so the engine doesn't over-heat or burn up anything in the exhaust path. Only run the engine for the absolute minimum time with the output hose in the bucket....